Process for dyeing acidyl celluloses



Patented Oct; 11, l92'7.

(UNITED STATES PATENT OFFICE.

PAUL BABE, OF LEVERKUSEN, NEAR COLOGNE, AND WILHELM SCHEPSS, OE 'WIES- DQRF, NEZAR COLOGNE, GERMANY, ASSIGNORS, BY MESNE ASSIGNMENTS,.TO GRAS- SELLI DYESTUFFCORPORATION, OF NEW YORK, N. Y., A. CORPORATION OF DELA- WARE.

PROCESS FOR DYEING ACIDYL OELLULOSES. I

No Drawing. Application filed March 3, 1924, Serial No. 696,675, and in Germany May 28 1 923.

It is well known that acidyl celluloses have v only a small absorptiv power for dyestufis. Attempts have, therefore, not been lackm to avoid this defect. A process is describe 5 for instance, in German Patent No. 355,533, which allows of the direct dyeing of cellulose acetate silk, by the addition to the dye-bath of one or more protective colloids, organic acids, and larger quantities of water-soluble 1o salts, particularly chlorides. British Patent 17 9,38% also recommends the employment of metallic salts such as sodium stannate, ma-

genta. etc., with the simultaneous addition of colloids. I

The noteworthy fact has now been established, that saltsof the oxy-acids 0t nitrogen and chlorine, as for instance, nitrates chlorates, nitrites etc. are-suitable in quite a peculiar degree, as additions in dyeing acidyl- 20 cellulose e. g., cellulose-acetate silk, lms etc. or their transformation products. The'use of protective colloids is superfluous. Even relatively small quantities of these salts produce shades of hitherto unattainable depth.

Example -1.1 part .by weight of chrysoi'dine Gextra is dissolved in 1000 parts by weight of water and '5 parts by weight of aniline nitrate are added. Ratio 1:20. Dyeing temperature Time'30 minutes. In-- 30 stead of aniline nitrate, the nitrates of ammonium, sodium, magnesium, calcium or zinc and further, of such'orgamc bases as mono;

meth lamine, dimethylamine etc., guanidine, pyri inc and piperidine, may be used.

7 Example 2.1 part by weight of crystal V nitrite are added. Dyeln is performed as acidyl celluloses are dyed in a bath contain- 2. Process I of dyeing --acidyl, celluloses violet P is dissolved in 1000 parts by weight I of water, and 5 parts by weight of sodium under 1. Chlorates may a so be used'instead of nit-rates. Other dyestuffs or their salts, as for instance, methylene ]o'l'ue, rhodulin red B, safranine, auraminegzBismark brown, rhodulin yellow, rhodulin blue 6G (nitrate), tur quoise blue. G, rhodamin 6G extra, new methylene blue F, and man others can be fixed on acetate cellulose sil s in this manner, with extraordinary de th of shade. Our applicationSer. No; 55,037 filed December 10, 1924; c'ontains'subject matter divided out of this application.

Weelaim: 1. Process of dyeing acid 1 celluloses characterized in and by the act that the ing' a dye and a salt of an oxy acid'of nitrogen.

characterized in and by thefact that the acidyl celluloses are dyed in a bath containing aniline nitrate.

3. A dyeing composition comprising a dye and a salt of an oxy acid of nitrogen with an organic base, I, r

4. A dyeing composition comprising a dye and aniline nitrate.

In' testimony whereof we haye hereunto set our hands.

' PAUL BABE. WILHELM SGHIEPSS. 

